• 대한치과교정학회지
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• 제52권2호
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• pp.131-141
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• 2022

Objective: The purpose of this study was to compare the differences in dentoskeletal and soft tissue changes following conventional tooth-borne rapid maxillary expansion (RME) between adolescents and adults. Methods: Dentoskeletal and soft tissue variables of 17 adolescents and 17 adults were analyzed on posteroanterior and lateral cephalograms and frontal photographs at pretreatment (T1) and after conventional RME using tooth-borne expanders (T2). Changes in variables within each group between T1 and T2 were analyzed using Wilcoxon signed-rank test. Mann-Whitney U test was used to determine the differences in the pretreatment age, expansion and post-expansion durations, and dentoskeletal and soft tissue changes after RME between the groups. Spearman's correlation between pretreatment age and transverse dentoskeletal changes in the adolescent group was calculated. Results: Despite similar amounts of expansion at the crown level in both groups, the adult group underwent less skeletal expansion with less intermolar root expansion after RME than the adolescent group. The skeletal vertical dimension increased significantly in both groups without significant intergroup difference. The anteroposterior position of the maxilla was maintained in both groups, while a greater backward displacement of the mandible was evident in the adult group than that in the adolescent group after RME. The soft tissue alar width increased in both groups without a significant intergroup difference. In the adolescent group, pretreatment age was not significantly correlated with transverse dentoskeletal changes. Conclusions: Conventional RME may induce similar soft tissue changes but different dentoskeletal changes between adolescents and adults.

• 사회복지연구
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• 제41권2호
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• pp.35-65
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• 2010

본 연구는 최근에 이루어진 '건강보험 보장성 확대' 정책의 효과를 개인의 의료이용 및 건강수준을 중심으로 평가하였다. 2005년부터 시행된 건강보험 보장성 확대 정책은 암 등의 중증질환자에 대한 본인부담 경감, 입원환자 식대의 급여전환, 비급여항목의 급여전환, 본인부담상한제 시행 등을 주요 내용으로 한다. 이러한 정책 변화에 대해 만성질환을 보유하고 있어 의료욕구가 일반적으로 높은 제도의 주요 수혜집단에 비해 급성질환 등으로 의료서비스를 이용한 집단의 입원이용이 상대적으로 증가한 것과 제도의 직접적인 수혜집단인 중증질환자 집단의 입원이용이 상당 정도 증가한 것을 확인하였다. 또한 이러한 건강보험제도의 변화가 입원이용에서 혜택을 누린 중증질환자의 단기간의 건강평가지표인 2주간 이환경험 면에서 긍정적인 개선을 이끌어내고 있음을 확인하였다. 본 연구는 건강보험제도가 의료이용 및 건강수준에 인과적인 효과를 나타내고 있음을 확인하였고, 이후 건강보험 보장성 확대의 정책설계에 대한 정책적 함의를 제공한다.

• 대한치과교정학회지
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• 제50권5호
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• pp.304-313
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• 2020

Objective: The aim of this study was to evaluate the stability of bimaxillary surgery involving bilateral intraoral vertical ramus osteotomy performed with or without presurgical miniscrew-assisted rapid palatal expansion (MARPE) in adult patients with skeletal Class III malocclusion. Methods: A total of 40 adult patients with skeletal Class III malocclusion were retrospectively divided into two groups (n = 20 each) according to the use of MARPE for the correction of transverse maxillomandibular discrepancy during presurgical orthodontic treatment. Serial lateral cephalograms and dental casts were analyzed until 6 months after surgery. Results: Before presurgical orthodontic treatment, there was no significant differences in terms of sex and age between groups. However, the difference of approximately 3.1 mm in the maxillomandibular intermolar width was statistically significant (p < 0.001). Two days after surgery, the mandible had moved backward and upward without any significant intergroup difference. Six months after surgery, the maxillary intercanine (2.7 ± 2.1 mm), interpremolar (3.6 ± 2.4 mm), and intermolar (2.0 ± 1.3 mm) arch widths were significantly increased (p < 0.001) relative to the values before presurgical orthodontic treatment in the MARPE group; these widths were maintained or decreased in the control group. However, there was no significant difference in surgical changes and the postsurgical stability between the two groups. No significant correlations existed between the amount of maxillary expansion and postsurgical mandibular movement. Conclusions: MARPE is useful for stable and nonsurgical expansion of the maxilla in adult patients with skeletal Class III malocclusion who are scheduled for bimaxillary surgery.

• 한국결정성장학회:학술대회논문집
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• 한국결정성장학회 2000년도 Proceedings of 2000 International Nano Crystals/Ceramics Forum and International Symposium on Intermaterials
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• pp.179-193
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• 2000

Aluminium titanate (Al₂TiO5) with an excellent thermal shock resistant and a low the expansion coefficient was obtained by solid solution with MgO, SiO₂, and ZrO₂ in the Al₂TiO5 lattice or in the grain boundary solution through electrofusion in an arc furnace. However, these materials have low mechanical strength due to the presence of microcracks developed by a large difference in thermal expansion coefficients along crystallographic axes. Pure Al₂TiO5 tends to decompose into α-Al₂O₃ and TiO₂-rutile in the temperature range of 750-1300℃ that rendered it apparently useless for industrial applications. Several thermal shock tests were performed: Long therm thermal annealing test at 1100℃ for 100h; and water quenching from 950 to room temperature (RT). Cyclic thermal expansion coefficients up to 1500℃ before and after decomposition tests was also measured using a dilatometer, changes in the microstructure, thermal expansion coefficients, Young's modulus and strengths were determined. The role of microcracks in relation to thermal shock resistance and thermal expansion coefficient is discussed.

• 대한기계학회논문집A
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• 제26권8호
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• pp.1615-1622
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• 2002

The purpose of this study is comparing cold expansion method with interference fit. Cold expansion method and interference fit of fastener hole is using in the aerospace industry. These treatment lead to an improvement of fatigue life to the compressive residual stresses developed on the hole surface. But Research is nothing to about difference effect of between cold expansion method and interference fit. So, this paper, it is shown that Comparing cold expansion method with interference fit using the finite element method. It is further shown that residual stress distribution according to plate thickness and clamping force.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.419-424
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• 2001

The purpose of this study is comparing cold expansion method with interference fit. Cold expansion method and interference fit of fastener hole is using in the aerospace industry. These treatment lead to an improvement of fatigue life to the compressive residual stresses developed on the hole surface. But Research is nothing to about difference effect of between cold expansion method and interference fit. So In this paper, It is shown that Comparing cold expansion method with interference fit. and It is further shown that residual stress distribution according to plate thickness.

• 대한기계학회논문집B
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• 제22권12호
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• pp.1669-1680
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• 1998

A method is developed to include the effect of volume expansion in the description of the flame dynamics using G-equation. Line volume-source is used to represent the effect of the exothermic process of combustion with source strength assigned by the density difference between the burned and the unburned region. The present model provides good agreement with the experimental results. Including volume expansion, the flow field is adjusted to accommodate the increased volume flow rate which crossing the flame front and the result predicts the same behavior of measured velocity field qualitatively. The effect of increasing volume expansion does not change the initial growth rate of flame area but increase the residence time. Consequently this effect increases the maximum area of flame front. The flame propagation in varying flow field due to volume expansion provides a promising way to represent the wrinkled turbulent premixed flames in a numerically efficient manner.

• 대한물리의학회지
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• 제9권1호
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• pp.11-23
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• 2014

PURPOSE: The purpose of this study suggests the exercise programs for improving the function and structure by applying the Schroth exercise method and sling exercise method to the scoliosis patient. METHODS: The subjects were 16 patients who were diagnosed with scoliosis. They were randomly assigned either to a Schroth exercise group (n=8) that received Schroth exercise program or to a sling exercise group (n=8) that received sling exercise program. Flexibility, static balance, dynamic balance, and spinal angles were measured by using the modified sit and reach test, one leg standing with closed eyes, functional reach test, and Cobb's angle, respectively. The chest expansion were calculated using differences of chest circumference between maximum inspiration and maximum expiration measured under armpits, at the junction between the sternum and xiphoid process, and at the waist. RESULT: Schroth group before and after the intervention there was a difference in the static balance, spine angle, chest expansion (p<.05). sling group before and after the intervention there was a difference in the flexibility, static balance, spine angle, chest expansion (p<.05). There were significantly differences between the both groups for chest expansion thoracic level inspiratory variables at post-exercise. CONCLUSION: These results revealed that two exercise program improved flexibility, static standing balance, spine angle, chest expansion level and ability used as scoliosis management and intervention. Therefore, it is expected to be used as a method for the treatment and prevention in the process of rehabilitation of patients with scoliosis.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.1243-1246
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• 1998

Three-dimensional(3-D) sound is a technique for generating or recreating sounds so they are perceived as emanating from locations in a three-dimensional space. Three dimensional sound has the potential of increasing the feeling of realism in music or movie soundtracks. Three-dimensional sound effects depend on psychoacoustic spectral and phase cues being presented in a reproduced signal. In this paper we propose an effective algorithm for the sound image expansion in television system using stereo image enhancement techniques. Compared to the other techniques of three-dimensional sound, the proposed algorithm use only two speakers to enhance the sound image expansion, while maintaining the original sound characteristics.

• Journal of applied mathematics & informatics
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• 제33권5_6호
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• pp.485-502
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• 2015

A computational method for solving singularly perturbed boundary value problem of differential equation with shift arguments of mixed type is presented. When shift arguments are sufficiently small (o(ε)), most of the existing method in the literature used Taylor's expansion to approximate the shift term. This procedure may lead to a bad approximation when the delay argument is of O(ε). The main idea for this work is to deal with constant shift arguments, which are independent of ε. In the present method, we construct the formally asymptotic solution of the problem using the method of composite expansion. The reduced problem is solved numerically by using operator compact implicit method, and the second problem is solved analytically. Error estimate is derived by using the maximum norm. Numerical examples are provided to support the theoretical results and to show the efficiency of the proposed method.